Bronchoscopic lung volume reduction valve

ABSTRACT

A one way valve for a biological flow passage includes an elongated braided structure sized for insertion in the biological flow passage, a portion of the braided structure forming a substantially tubular shell, the braided structure maintaining an expanded operative shape after being deformed to a small dimension; a non-porous coating of the braided structure; a constricted portion of the elongated braided structure disposed between a proximal end and a distal end thereof, the constricted portion closing off a channel of the braided structure and defining at least one funnel shaped region of the braided structure to prevent flow towards the distal end; at least one hole formed in the non-porous coating, permitting a flow of one of air and fluid towards the proximal end; and an anchoring portion to retain the one way valve in a selected location within the biological flow passage.

PRIORITY CLAIM

The present application is a Continuation of U.S. patent applicationsSer. No. 11/250,968 filed on Oct. 14, 2005, now U.S. Pat. No. 9,265,605.The entire disclosure of the above patent is expressly incorporatedherein by reference.

BACKGROUND

Emphysema is a chronic, progressive disease of the lungs which affectsmillions of Americans. Patients affected with emphysema have a difficulttime breathing. Emphysema is not presently curable, but it can betreated. Emphysema often is a result of chronic infection or irritationof the bronchial tubes. The bronchial tubes extend from the windpipe tothe lungs, and look like branches of a tree, with the branches becomingsmaller and smaller until each one ends in a cluster of small air spacesin the lung, called alveoli. When the bronchi become irritated, some ofthe airways may be obstructed, trapping air in the lung beyond them. Thewalls of the tiny air spaces may become damaged and may tear. If thestretching and destruction of the walls of the alveoli continues,portions of the lungs may become enlarged, at the same time becomingless efficient in exchanging oxygen for carbon dioxide. Healthy portionsof the lungs may be compressed by the diseased lung portions.

Lung volume reduction surgery is one treatment used to relieve thesymptoms of emphysema. The surgery creates more room for the patients'lungs by removing portions of the overly distended diseased lung. Up to20-30% of each lung may be removed to allow more space for the remainingportion of the lung to inflate. While not a cure for emphysema, thesurgery does afford many patients the opportunity to lead healthier,more active lives. Lung volume reduction surgery (LVRS) has been shownto improve pulmonary function, exercise capacity, quality of life andsurvival rate in selected patients. However, LVRS is a major surgicalprocedure with complications and potential morbidity and mortality, andis not suited for patients that may be weak, or otherwise unable toundertake major surgery.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to a valve to performlung volume reduction procedures, which comprises a braided structureadapted for endoscopic insertion in a bronchial passage, the braidedstructure having a proximal end and a distal end, a non porous coatingadapted to prevent flow of air through the braided structure, aconstricted portion of the braided structure preventing flow of airthrough a tubular central lumen of said braided structure, and defininga funnel shaped portion thereof, and at least one hole of the braidedstructure adapted to permit flow of mucus from the distal end to theproximal end. The funnel shaped portion is adapted to prevent flow ofair from the proximal end to the distal end.

In a different aspect, the invention is directed to a one way valve fora biological flow passage. The valve comprises an elongated braidedstructure sized for insertion in the biological flow passage, a portionof the braided structure forming a substantially tubular shell, thebraided structure maintaining an expanded operative shape after beingtemporarily compressed, a non porous coating of the braided structure, aconstricted portion of the elongated braided structure disposed betweena proximal end and a distal end thereof, the constricted portiondefining at least one funnel shaped region of the braided structureimpeding flow towards the distal end, and at least one hole formed inthe non porous coating, permitting a flow of fluid towards the proximalend.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a first embodiment of a lung volumereduction valve according to the present invention;

FIG. 2 is a diagram showing a second embodiment of a lung volumereduction valve according to the present invention, with an anchoringmechanism;

FIG. 3 is a diagram showing a third embodiment of a lung volumereduction valve according to the present invention, with a retrievalrod;

FIG. 4 is a diagram showing a fourth embodiment of a lung volumereduction valve according to the present invention, with a secondary oneway valve;

FIG. 5 is a diagram showing another embodiment of a lung volumereduction valve according to the present invention, with an exemplaryanchoring structure;

FIG. 6 is a diagram showing yet another embodiment of a lung volumereduction valve according to the present invention, with anotheranchoring structure; and

FIG. 7 is a diagram showing a different embodiment of a lung volumereduction valve according to the present invention, with a zig zag ring.

DETAILED DESCRIPTION

The present invention may be further understood with reference to thefollowing description and the appended drawings, wherein like elementsare referred to with the same reference numerals. The present inventionis related to medical devices used to provide unidirectional flow withinbiological flow passages. More specifically, the invention is related tomedical devices used to control the flow of air and of mucus within thebronchial passages of a lung.

The exemplary embodiments of the present invention described hereinrelate to a one way valve which can be used to control the flow of a gasthrough a biological flow passage. In one example, the one way valve isused during lung volume reduction procedures which are often performedto alleviate the symptoms of emphysema. The one way valve may be used torestrict the flow of air reaching selected portions of the lungs, and atthe same time to permit the flow of residual air and/or mucus and otherfluids out of the lung. The exemplary valve according to the inventionmay comprise a braided tubular structure that is constricted at one endor in the middle. The braided structure may be covered with a non-porouscoating, and may include openings or a secondary additional valve toallow passage of mucus across the valve.

Lung Volume Reduction (LVR) surgery is a medical technique used to treatemphysema. Although the procedure does not provide a cure to emphysema,it often alleviates the symptoms of the disease, and can significantlyimprove the quality of life of the patient. Emphysema results fromchronic infection or irritation of the bronchial tubes, often caused bysmoking, pollution, or other environmental and genetic factors. Thebronchial tubes extend from the windpipe to the lungs, and look likebranches of a tree, with the branches becoming smaller and smaller untileach one ends in a cluster of small air spaces in the lungs, calledalveoli. Emphysema causes some of the airways to become irritated andobstructed, trapping air in the lung beyond them. The walls of thealveoli in that region of the lung may become damaged and may tear. Ifthe stretching and destruction of the walls of the air spaces continues,portions of the lungs may become enlarged, while at the same timebecoming less efficient in exchanging oxygen for carbon dioxide.

In more advanced stages of the disease, healthy portions of the lungsmay be compressed by the diseased and enlarged lung portions. Thediaphragm of the patient also may be compressed by the enlarged lungtissue, so that taking every breath becomes a difficult and tiringprocess. The patient is faced with the dual challenges of breathing withonly a portion of the lungs being functional, and with the additionaldifficulty of filling those functional portions with air against thepressure of the enlarged lungs. Conventional LVR surgery has been usedto alleviate these difficulties. During the procedure, some of thediseased portions of the lung or lungs are removed via an openthoracotomy. About 20% to 30% of each lung may be removed in this majorsurgical operation, which is complex and has a high morbidity rate. Thebenefit of removing the enlarged, diseased portions of the lungs is thatmore room is left in the thoracic cavity where the remaining portion ofeach lung can expand.

Less intrusive procedures have been developed to achieve results similarto those of the open chest LVR procedures, without the associatedcomplications and high morbidity rates. Principally, these lessintrusive procedures involve depositing in the lungs devices thatrestrict the flow of air to the diseased portions of the lungs. Often, abronchoscope is used to deliver the devices, without having to resort tocutting through the chest of the patient. The devices may be valves,which are placed in the bronchial passages leading to the affectedportions of the lungs, or some other form of flow blockage, whichprevents air from reaching the diseased portions. When a valve is usedto prevent air from reaching selected portions of the lung, it isimportant to ensure that mucus can be expelled from those portions. Abuildup of mucus in the lungs may lead to infections and other seriouscomplications. Accordingly, it is desirable to provide valves thatpermit residual air and mucus to exit the lung, while preventing airfrom flowing therein.

Various devices and structures have been used in medical procedures toocclude the flow of a fluid in a biological flow passage or vessel. Forexample, it is often useful to restrict the flow of blood through a veinor artery. These devices generally consist of a braided metallicstructure similar to a Wallstent© flexible tube, which is madeimpermeable with a polymeric coating. The flexible braided tube isconstricted near its middle portion, into a shape similar to that of anhourglass. Alternatively, the braided tube may be constricted at oneend, to form a cylindrical shell with one end terminating in a point.Examples of a flexible braided tube used for occluding the flow of afluid through a blood vessel are described in U.S. Pat. No. 5,919,224,assigned to Schneider USA Inc., whose subject matter is herebyincorporated in its entirety by reference.

Structures similar to the one described above have been used also asfilters placed in the bloodstream, for example to capture blood clotsand prevent them from traveling through the patient's vascular system.U.S. Pat. No. 5,836,969 assigned to Boston Scientific describes one suchfilters, with an anchoring mechanism to retain it in place in apatient's vena cava. The anchoring mechanism consists of projectingwires and hooks, and serves to retain the filter against the force ofthe blood flowing in the vessel. In this manner the filter can be leftin the patient's body for extended periods of time, without beingdisplaced by the force of the flowing blood, or by the normal activitiesof the patient. The subject matter of the '969 patent is herebyincorporated by reference in its entirety.

The various embodiments of the present invention described hereinprovide for a one way valve used in bronchoscopic lung volume reductionprocedures. In one more specific example, the valve consists of abraided structure with looped ends that is constricted in its middle.The structure may be fully or partially covered with a non-porousmaterial which prevents the passage of air therethrough, so that thedevice may prevent the flow of air through the bronchial passages, atleast in one direction. In one embodiment, some holes are formed at thedistal end of the structure, to permit the passage of mucus out of thelungs through the distal part of the structure, then between the wall ofthe proximal part of the structure and the bronchial vessel, while atthe same time preventing the inflow of air therein. An anti-microbialcoating may also be applied to the device, to lessen the likelihood ofan infection developing at the site of the valve.

FIG. 1 shows a diagram of an exemplary embodiment of a one way valveaccording to the present invention. The exemplary one way valve 100comprises an elongated braided structure 102, which may be madepreferably of a material such as Nitinol, MP35N, or Elgiloy. Othermaterials, preferably having shape memory properties and/orsuper-elastic properties, may also be used to construct the elongatedbraided structure 102. An example of another material may be a shapememory polymer. Such a plastically deformable material may be insertedinto the bronchial tube using a tool or a balloon. The braided structure102 may be designed to return to an operative, expanded configurationafter being deformed by a constraining force. For example, the braidedstructure 102 may be compressed during deployment through a catheter, tofit through a small working channel. After deployment from the catheter,the braided structure 102 expands back to the original shape anddimensions, and occupies substantially the entire cross section of thebronchial channel where it is deployed.

A coating 112 may be applied to a portion or to substantially all of thesurfaces of the braided structure 102. For example, the coating maycomprise a non-porous polymeric material such as silicone, polyurethane,polyethylene terephthalate (PET), Polytetrafluoroethlylene (PTFE), etc.The non-porous material prevents the passage of fluids through thesurfaces of the braided structure 102, so that it is effective inrestricting the flow of air through the bronchial passage. The one wayvalve 100 has a distal end 106 which faces towards the alveoli of thelungs when placed within a bronchial passage, and a proximal end 104which faces towards the trachea of the patient.

The braided structure 102 may have a substantially tubular elongatedshell, similar to the structure of a braided stent, and may comprise aconstricted portion 108 which is located longitudinally near the middleof the one way valve 100. The constricted portion 108 forms at least onefunnel shaped portion of the braided structure 102, and in theembodiment shown in FIG. 1 forms two funnel shaped portions. Each of thefunnel shaped portions prevents the flow of air in the direction towardsthe constricted portion 108. The narrowing of the constricted portion108 may be achieved by applying an external force on the braidedstructure 102, such as with a band or a clip 114, or may be obtained byappropriate conventional manufacturing steps. The constricted portion108 of the braided structure 102 also provides the desired one-way valveeffect by substantially closing off the tubular channel formed withinthe braided structure 102.

When inserted into one of a patient's bronchial tubes, the proximal end104 of the valve 100 faces toward the patent's trachea, while the distalend 106 faces toward the alveoli, i.e., the diseased portion of thelung. The outer diameter of the structure is selected to be slightlylarger than the diameter of the bronchial tube. The valve 100 may alsoinclude a coating or an adhesive on the outside to allow it to adhere tothe bronchial tube. Thus, when the patient inhales and air travelsthrough the trachea toward the lung, the inhaled air that enters thebronchial tube having the valve 100 will be prevented from passingthrough the valve 100 and into the diseased portion of the lung. Thisinhaled air will enter the funnel shaped portion of the proximal end 104and may cause the funnel shaped portion to radially expand causing thebraided structure 102 to better contact the inner walls of the bronchialtube. This radial expansion may improve the seal around the outsideradius of the distal end 104. This outer tight seal and the innerconstricted portion 108 allows little or no air to flow to the diseasedportion of the lung. Thus, the valve 100 acts as an obstruction devicewhen the patient inhales air. The exhale direction will be discussed ingreater detail below.

The exemplary one way valve 100 shown in FIG. 1 may be compressed to adiameter that is smaller than its expanded, unconstrained diameter, andmay be placed in the working channel of a small diameter catheter fordelivery to the desired location. For example, a bronchoscope may beused to deliver the device to a bronchial passage between the patient'strachea and the alveoli found deep into the lungs. When the one wayvalve 100 is deployed from the catheter, it expands to its operativedimensions within the bronchi. For example, the shape memory propertiesof the materials used to form the braided structure 102 may promote thereturn to a preselected shape after being constrained. At least theproximal end 104 of the braided structure 102 expands to a diametersufficient to encompass the internal dimensions of the bronchialpassage, so that the flow of air may be restricted therethrough.

According to exemplary embodiments of the invention, the one way valve100 may be made of polymeric or metallic filaments, which form thebraided structure 102. The filaments may comprise a radiopaque componentto improve the device's radiopacity, so that the operating surgeon isable to place the device in the patient's lungs more accurately. Forexample, if the braided structure 102 is made of a polymeric material, aradiopaque agent such as a metallic or ceramic powder may be included inthe material during the manufacturing process. Alternatively, thepolymer may include elements having a high atomic number such as iodinein its chemistry. If the braided structure is made out of metallicwires, a portion or all of these wires may have a radiopaque core. Theconstricted portion 108 may be constrained, for example, by a metallicring 114, which can be of a radiopaque material. Other radiopaquedevices and/or methods may also be used to provide the operating surgeonwith a better view of the valve while it is being placed into thebronchial tubes, e.g., radiopaque markers and radiopaque paint. Theproximal and distal ends 104, 106 of the braided structure 102 aredesigned to be atraumatic, to prevent injury to the trachea and to thebronchial passages when they are inserted into the lungs. For example,the extremities may be looped, so that there are no sharp strands orwires extending from the device, or they may be welded, also to form asmooth end surface.

One or more holes 110 are visible in the exemplary embodiment shown inFIG. 1. The holes are formed in the distal portion of the braidedstructure 102, and are designed to allow for residual air and mucusclearance from the lungs. The holes 110 may be formed in the non-porouscoating 112 of the one way valve 100, while leaving the braids of thebraided structure 102 unaffected. Alternatively, the holes 110 may becut through the entire device, including the braided structure 102. Theholes 110 are preferably located close to the constricted region 108 ofthe one way valve 100, away from the surrounding walls of the bronchialpassage, or from the other biological structures in which the valve 100may be inserted. The location of the holes 110 away from the inner wallsof the passage avoids tissue ingrowth into the exposed braidedstructure, and makes the device more easily removable from the lungs ofthe patient even after a prolonged stay.

When a patient exhales or coughs the direction of the air and/or fluidflow will be from the alveoli through the bronchial passage to thetrachea. If the valve 100 was simply a constriction device, thisair/fluid flow would be eliminated in the same manner as described abovefor the inhale air flow. However, the valve 100 includes the holes 110which transform the valve 100 into a one way valve allowing forair/fluid flow in the exhale direction as will be described. Asdescribed above, mucus and other fluids may build up in the diseasedportion of the lung. This mucus must be allowed to be cleared from thelung. Similarly, even though little or no air will be entering thealveoli, there may be residual air in the alveoli because it is notphysically possible during normal breathing to completely exhale all theair out of the lungs. In addition, because the diseased alveoli breakdown, there may be seepage of air from other alveoli into the alveoliconnected to the blocked bronchial passage.

Thus, when exhaling or coughing, the air will flow from the alveoli tothe funnel shaped portion of the distal end 106 of the valve 100. Asdescribed above for the proximal end 104, this air may cause the funnelportion to expand radially to form a tight seal between the distal end106 and the bronchial passage. In a further exemplary embodiment, thedistal end 106 may be sized slightly larger than the proximal end 104 inorder to provide a continuous tight seal and securely anchor the valve100 in the bronchial passage 100 or conversely. In addition, an increasein the length of the distal end 106 may also provide a better anchoringfor the valve 100. The valve 100 may also include anchors so that thevalve 100 is securely placed in the bronchial tube. In the exemplaryembodiment of FIG. 1, the anchors may be placed in any position alongthe outer body of the valve 100 including in the area of the constrictedportion 108.

In any case, as the air/fluid flows into the funnel portion of thedistal end 106, it may then flow out of the holes 110 in the valve 100.This air/fluid will then be in the cavity between the constrictedportion 108 and the bronchial passage. However, since the air/fluid istraveling in the exhale direction, this may cause the funnel portion ofthe proximal end 104 to radially contract allowing the air/fluid to flowout of the lung and be exhaled/discharged. Thus, the valve 100 acts as aconstriction device for air flow in the inhale direction, but as an openvalve for air/fluid flow in the exhale direction.

In a different embodiment, the constricted portion 108 may be located ata different location along the length of the valve 100. For example, theconstriction may be formed near the distal end 106, to prevent the flowof air into the lung. In general, the constriction may be formed at anylocation which allows the proximal end 104 to expand to a diametersufficient to completely block the bronchial tube in which the device isplaced. FIG. 2 shows an exemplary one way valve 200, in which theconstriction 208 is formed near the distal end 206 of the device. Inthis exemplary embodiment, the constricted portion 208 forms only onefunnel shaped portion of the device. When valve 200 is placed in a fluidmoving towards the constriction 208 (i.e., air flowing in the inhaledirection), the proximal end 204 is pushed radially outward by the flow,and causes the braided structure 202 to better contact the inner wallsof the bronchial passage preventing air flow into the diseased portionof the lung. When air/fluid is traveling in the exhale direction, thefunnel portion of the proximal end 204 may be radially constricted toallow the air/fluid to be exhaled/discharged.

Continuing with the exemplary embodiment of the FIG. 2, the distalportion 206 of the braided structure 202 has been replaced with ananchoring mechanism 210. The anchoring mechanism 210 may be, forexample, similar to the anchoring mechanism described in U.S. Pat. No.5,836,969. In one exemplary embodiment, the anchoring mechanism 210 maycomprise a plurality of grasping wires such as shape memory wires 212,that may be made of Nitinol or of another suitable shape-memorymaterial. The wires 212 may extend in a deployed configuration so thatprotrusions 214 formed at the tip of the wires 212 can engage the tissueof the bronchial passages in which the device is deployed. The anchoringmechanism 210 prevents undesired movement of the one way valve 200 fromits desired location.

Another embodiment of the valve according to the present invention isshown in FIG. 3. Here, a retrieval mechanism is added to the proximalportion of the one way valve 250. An extending rod 270 passes throughthe tubular proximal portion of the braided structure 252, for exampleextending from the constricted portion 258. A loop or hook 272 may beprovided at the proximal end of the extending rod 270, to facilitateretrieval of the device from the patient's lung. Repositioning of thedevice within the bronchial passage may also be accomplished by graspingit by the extension rod 270 and/or the loop 272. For example, forceps orother similar instruments may be used to endoscopically manipulate theone way valve 250.

In other embodiments, the retrieval mechanism may also include aretrieval loop disposed at the proximal end of the braided structure252. For example, a retrieval loop 274 may be formed, extending from anedge of the braided structure 252 to another edge or to the extendingrod 270. The retrieval loop 274 may be threaded around the proximalportion of the braided structure 252, and may comprise a plurality ofloops and projections to improve the retrieval ability of the device.The loops and projections of the retrieval loop 274 may be polymeric ormetallic, and may preferably comprise shape memory materials such asNitinol.

In general, clearing of the mucus from the inner parts of the lungstructure is likely to take place between the bronchi and the body ofthe valve. To facilitate the process, the exemplary embodiment shown inFIG. 4 comprises a secondary one way valve in the constricted portion.For example, the secondary one way valve 300 may comprise a valve body310 disposed in the constricted portion 308, distally from the proximalend 304 of the expanded braided structure 302. The valve 310 may be aball valve, a leaflet valve, a lip valve, a duckbill valve or a socketvalve. Additional types of valves may also be used, to permit the flowof mucus from the lungs towards the trachea, in the direction towardsthe proximal end 304. The mucus may be expelled from the lungs throughthe secondary valve 310 by coughing and by the normal operation of thelungs.

Additional devices may be used to help anchor the one way valve withinthe bronchial passage or within other tubular structures of thepatient's body. For example, as shown in FIG. 5, an anchoring flare 406may be formed at the proximal end 404 of the braided structure 402. Inthis manner, the one way valve 400 may remain in place despite themovements caused by the daily activities of the patient, and despite theforce applied by air moving through the lungs. In particular, the forceof the air when the patient coughs may be very large, and may require astrong anchor. FIG. 6 shows another exemplary embodiment of an anchoringmechanism. In this case, the valve 450 has a bulge 456 formed on thebraided structure 452. The bulge 456 and the flare 406 may be formed onthe proximal part of the structure, as shown, or on the distal part of astructure similar to that shown in FIG. 1.

Yet another anchoring mechanism for an exemplary valve is shown in FIG.7. In this exemplary embodiment, the one way valve 500 comprises abraided structure 502 having a constricted portion 508 at its distalend. An anchoring mechanism 510 is disposed at the distal end of thevalve 500, and is designed to expand to a dimension substantiallysimilar to the inner dimension of the bronchial passage. A zig zag ring514 connected to the braided structure 502 by extending wires 512 may beused to anchor the device in place, when in the deployed configuration.A shape memory material such as Nitinol may be used to form theextending wires 412 and the zig zag ring 514, to ensure that theanchoring mechanism 510 expands to the desired shape and dimension afterbeing compressed to a small size for deployed from a catheter or from abronchoscope.

The present invention has been described with reference to specificexemplary embodiments. Those skilled in the art will understand thatchanges may be made in details, particularly in matters of shape, size,material and arrangement of parts without departing from the teaching ofthe invention. Additional organs may be treated by using the presentinvention, in addition to the lungs. Accordingly, various modificationsand changes may be made to the embodiments without departing from thebroadest scope of the invention as set forth in the claims that follow.The specifications and drawings are, therefore, to be regarded in anillustrative rather than a restrictive sense.

What is claimed is:
 1. A one way valve for a biological flow passage,comprising: an elongated braided structure sized for insertion in thebiological flow passage, a portion of the braided structure forming asubstantially tubular shell, the braided structure maintaining anexpanded operative shape after being deformed to a small dimension; anon porous coating of the braided structure; a constricted portion ofthe elongated braided structure disposed between a proximal end and adistal end thereof, the constricted portion closing off a channel of thebraided structure and defining at least one funnel shaped region of thebraided structure to prevent flow towards the distal end; at least onehole formed in the non porous coating, permitting a flow of one of airand fluid towards the proximal end; and an anchoring portion to retainthe one way valve in a selected location within the biological flowpassage.
 2. The one way valve according to claim 1, wherein theanchoring portion comprises grasping wires extending distally from thebraided structure to engage walls of the biological flow passage.
 3. Theone way valve according to claim 2, wherein the grasping wires retain aselected shape after being deformed during insertion.
 4. The one wayvalve according to claim 1, wherein the anchoring portion comprises atleast one of flares and bulges of the braided structure, to engage wallsof the biological flow passage.
 5. The one way valve according to claim1, wherein the anchoring portion comprises a shape memory zig zag ringextending from the braided structure.
 6. The one way valve according toclaim 1, further comprising: one of a grasping rod and grasping wiresextending proximally to facilitate retrieval.
 7. The one way valveaccording to claim 1, further comprising: a secondary one way valvedisposed in the constricted portion.
 8. A valve to perform lung volumereduction procedures, comprising: a braided structure adapted forendoscopic insertion in a bronchial passage, the braided structurehaving a proximal end and a distal end; a non porous coating adapted toprevent flow of air through the braided structure; a constricted portionof the braided structure closing a central lumen of said braidedstructure to prevent a flow of air therethrough, and defining a funnelshaped portion thereof; a valve structure adapted to permit expulsion ofmucus from the distal end to the proximal end; and an anchor portionextending from the braided structure, wherein the funnel shaped portionis adapted to prevent flow of air from the proximal end to the distalend.
 9. The valve according to claim 8, wherein the valve structure is aone way valve disposed substantially at the constricted portion.
 10. Thevalve according to claim 8, wherein the anchor portion comprises shapememory grasping wires adapted to engage an inner surface of thebronchial passage.
 11. The valve according to claim 10, furthercomprising: a zig zag ring disposed on the grasping wires adapted toengage the inner surface of the bronchial passage.
 12. The valveaccording to claim 8, wherein the anchor portion comprises at least oneof a flare and a bulge of the braided structure.
 13. The valve accordingto claim 8, wherein the constricted portion is disposed at the distalend of the braided structure.
 14. The valve according to claim 8,further comprising: a retrieval portion to facilitate endoscopicretrieval.
 15. The valve according to claim 14, wherein the retrievalportion comprises at least one of an extending rod, and of retrievalloops and projections extending proximally from the braided portion. 16.The valve according to claim 8, wherein the valve structure is at leastone hole through the braided structure and the non-porous coating. 17.The valve according to claim 16, further comprising: a secondary one wayvalve disposed substantially at the constricted portion.